OPTIONS AND RESULTS FOR THE MANAGEMENT OF MINIMALLY INVASIVE, CARCINOMA OF THE BREAST - INFLUENCE OF AXILLARY DISSECTION FOR TREATMENT OF T1A AND T1B LESIONS

BACKGROUND: Axillary dissection has maintained a role of primacy for t he surgical therapy of invasive carcinoma of the breast for many years . More recently, early (T1) minimally invasive carcinoma of the breast has been diagnosed with increasing frequency, and the necessity of ax illary dissection for sampling purposes in these small tumors has been questioned, based primarily on the finding of low rates of axillary m etastases. STUDY DESIGN: The Rhode Island State Tumor Registry records of 1,126 patients with T1a or T1b tumors were examined to assess the effect of axillary dissection on patient outcome. These data span 9 ye ars (1985 to 1992) with a median follow-up duration of 64 months. Five -year overall, disease-free, and breast cancer-specific (determinate) survival were determined according to treatment modality. Axillary nod e positivity was calculated for patients with minimally invasive carci noma of the breast who underwent axillary dissection. Multivariate sta tistical methods were used to provide adjustment for known confounding prognostic variables. RESULTS: Omission of axillary dissection occurr ed in 157 cases and correlated with reductions in overall, disease-fre e, and breast cancer-specific survival (p<.001 in all cases). Nodal st atus significantly influenced disease-free survival in minimally invas ive carcinoma of the breast (90 percent node-negative compared with 76 percent node-positive, p=.02). Nodal positivity was evident in 18.2 p ercent of patients undergoing axillary dissection for minimally invasi ve carcinoma of the breast (9.8 percent for T1a, 19.4 percent for T1b, p=.01). In multivariate analysis, the performance of axillary dissect ion with breast conservation or modified radical mastectomy were indep endent predictors of overall survival, as well as disease-free and bre ast cancer-specific survival. CONCLUSIONS: A significant number of pat ients with small (less than or equal to 1 cm) invasive tumors of the b reast will have axillary metastases at the time of diagnosis. Omission of axillary dissection in these patients was associated with signific ant impairment of overall, disease-free, and breast cancer-specific su rvival. Axillary dissection should continue to be a standard approach for the surgical therapy of all patients with invasive carcinoma of th e breast, regardless of tumor size.